Apparatus and method for detecting error of transfer system

Abstract

An apparatus for detecting error of a transfer system that is adapted for detecting an error of a transfer system transferring a substrate loaded upon fabricating of a flat panel display device in a real time is disclosed. In the apparatus, an emitter generates a light and radiates the light into a transfer system. A receiver receives light reflected from the transfer system. A controller controls light radiation from the emitter, and measures the time such that a reflective light of the transfer system is received from an emitting point of the emitter to the receiver. The controller also detects a displacement of the transfer system using the measured time, a designated reference distance and a reference time. A display displays the displacement of the transfer system detected by the controller.

What is claimed is: 
     
       1. An apparatus for detecting an error in a transfer system, comprising:
 an emitter for generating a light and for radiating into the transfer system; 
 a receiver for receiving the light reflected from the transfer system; 
 a controller coupled with the receiver that controls light radiation of the emitter and that times a measured time from when the reflective light of the transfer system is received from an emitting point of the emitter to the receiver, wherein the controller detects a displacement of the transfer system using the measured time, a designated reference distance and a reference time; and 
 a display coupled with the controller that displays a displacement of the transfer system detected by the controller. 
 
     
     
       2. The apparatus of  claim 1 , wherein the controller inserts the measured time into a designated equation in which a designated reference distance and a designated reference time are used to detect a distance between the emitter and the transfer system. 
     
     
       3. The apparatus of  claim 2 , wherein the controller detects a maximum linear distance between the emitter and the transfer system by the designated equation. 
     
     
       4. The apparatus of  claim 3 , wherein the controller subtracts the designated reference distance from the detected distance to detect a displacement of the transfer system. 
     
     
       5. The apparatus of  claim 1 , wherein the controller displays the displacement of the detected transfer system and error information of the transfer system on the display. 
     
     
       6. An apparatus for detecting error of a transfer system, comprising:
 an emitter for generating a light and for radiating the light into the transfer system; 
 a receiver for receiving a reflected light from the transfer system; 
 a controller coupled with the receiver and for detecting an error using an intensity of the reflected light sensed by the receiver and an intensity of a designated reference light; and 
 a display coupled with the controller and for displaying error information of the transfer system detected by the controller, 
 wherein the controller compares an intensity of the reflected light with the designated reference light to determine if there is an error of the transfer system. 
 
     
     
       7. The apparatus of  claim 6 , wherein if the intensity of the reflected light and the designated reference light intensity are the same, the transfer system is normal and there is no error. 
     
     
       8. The apparatus of  claim 6 , wherein if the intensity of the reflected light is weaker than the designated reference light intensity, the controller knows that an error is generated in the transfer system. 
     
     
       9. A method for detecting error of a transfer system, comprising:
 generating a light and radiating the light into the transfer system; 
 starting a timer to measure a recorded time upon generating the light; 
 receiving a reflective light from the transfer system and stopping the timer in response to receiving the reflective light; 
 detecting a displacement of the transfer system using the recorded time, a designated reference distance and a designated reference time; and 
 displaying the displacement of the detected transfer system. 
 
     
     
       10. The method as in  claim 9 , wherein the recorded time is inserted into a designated equation in which the designated reference distance and the designated reference time are used to detect a distance for detecting a displacement of the transfer system. 
     
     
       11. The method as in  claim 10 , wherein the equation is t1:s1=t2:s2,wherein the t1 represents the designated reference time from that a light radiated from the emitter and reflected by the transfer system of a normal horizontal state to that the light is received into the receiver, the s1 represents the designated reference distance between the emitter and the transfer system, the t2 represents the recorded time, the s2 represents a linear distance between the emitter and the transfer system calculated by the equation. 
     
     
       12. The method as in  claim 11 , wherein the designated reference distance is subtracted from the linear distance to detect a displacement of the transfer system. 
     
     
       13. The method as in  claim 9 , wherein the displacement of the detected transfer system, and error information of the transfer system are displayed on the display. 
     
     
       14. A method for detecting error of a transfer system, comprising:
 generating a light and radiating the light into the transfer system; 
 sensing an intensity of a reflective light reflected by the transfer system; 
 detecting an error of the transfer system by using the intensity of the reflective light and a designated reference light intensity; and 
 displaying the detected error of the transfer system, 
 wherein the detecting step includes comparing whether or not an intensity of the reflective light is weaker than that of the designated reference light to identify an error of the transfer system. 
 
     
     
       15. The method as in  claim 14 , wherein if the intensity of the reflective light and the designated reference light intensity are the same, the transfer system is normal. 
     
     
       16. The method as in  claim 14 , wherein if the intensity of the reflective light is weaker than the designated reference light intensity, the transfer system identifies the error. 
     
     
       17. The method as in  claim 14 , wherein the intensity of the reflective light is in proportion to light quantity. 
     
     
       18. The method as in  claim 14 , wherein the error comprises at least one of a displacement of the transfer system, a transformation of the transfer system, or combinations thereof.